Tol.  49. _ 
AHBIVEBSAKT  ADDRESS  OR  IDE  PRZSTDEST. 
79 
though  the  evidence  on  this  point  requires  farther  working  out. 
Altogether,  since  the  new  reading,  the  evidence  as  to  the  amount  of 
sculpture  effected,  in  the  immediate  neighbourhood  posterior  to  the 
deposit  of  the  Elephant-remains  is  not  of  so  decided  a  character  as 
under  the  old  hypothesise 
A  : . * /: Z  .  1'  —  vTe  must  now  turn  from 
the  Pleistocene  Geology  of  the  southern  counties  to  the  more  certain 
evidences  of  glacial  action  in  the  Xorth  midlands.  La  this  connexion 
we  have  a  paper  by  Mr.  Deeley  on  the  Pleistocene  succession 
in  the  Trent  basin,  more  especially  in  the  vicinity  of  the  junction 
of  the  Derwent  with  that  river.  As  the  outcome  of  seven  years  of 
careful  observation  from  IS 79  to  1SS6,  this  paper  should  carry 
some  weight  with  it.  The  Pleistocene  deposits  of  the  Trent  basin 
are.  he  says,  chiefly  remarkable  for  the  great  development  which 
the  Glacial  beds  attain :  these  consist  of  Boulder-clays,  gravels,  and 
sands  of  various  kinds  and  ages.  The  distribution  of  Boulder-dav 
varies  much,  both  as  regards  age  and  thickness,  for  in  some  localities 
it  occurs  in  great  masses  occupying  small  areas,  and  in  others 
it  covers  considerable  districts  with  a  tolerably  uniform  mantle. 
In  the  Trent  basin,  as  in  that  of  the  Thames,  the  Older  Pleistocene 
deposits  are  distinguished  from  those  of  later  age  by  their  freedom 
from  Cretaceous  rock-debris.  This  Older  Pleistocene  consists  of 
two  Boulder-clays  separated  by  a  quartzose  sand.  These  Pennine 
Boulder-clays,  as  Hr.  Deeley  calls  them,  are  composed  of  materials 
derived  almost  entirelv  from  the  Derbvshire  highlands,  with  a  slight 
admixture  to  the  westward  of  erratics  from  Scotland  and  elsewhere. 
The  bulk  of  the  materials  were  transported  from  the  Pennine  chain 
by  glaciers,  and  deposited  in  what  he  regards  as  the  partially  sub¬ 
merged  valley  of  the  Trent,  *'■  The  conditions  of  climate  which 
gave  rise  to  the  formation  of  the  early  Pennine  glaciers,  and  which 
passed  away  with  the  increasing  submergence  of  the  Quartzose-sand 
sea,  again  returned  :  for  upon  the  Quartzose  sand  there  are  thick 
deposits  of  Boulder-clay,  giving  evidence  of  intense  glacial  con¬ 
ditions. I  have  quoted  this  last  passage  verbatim,  as  it  shows  the 
1  The  following  is  an  extract  from  a  letter  written  to  me  by  Mr.  Mansel- 
P.eydell  on  this  subject  last  autumn : — •  Perhaps  you  will  kindly  add  a  note  to 
your  remarks  upon  the  Dewlish  bed.  namely,  that  my  paper  in  the  Proceedings 
of  the  Dorset  Field  Club  was  written  before  I  had  traced  it  from  end  to  end. 
Instead  of  its  being  a  pocket  at  a  higher  level  than  that  of  the  present  stream, 
as  I  supposed,  it  is  a  fissure  in  the  Chalk  into  which  the  Elephant-remains, 
flints,  etc.,  fell  in  as  the  Pliocene  (?)  stream  passed  over  it.  and  of  which  no 
other  evidence  is  left! 
